[Synthesis of new pyrido-(3',2':4,5)-thieno-(3,2-d)-1,2,3-triazine derivatives as antianaphylactics].

Some new pyrido[3',2':4,5]thieno[3,2-d]1,2,3-triazine-4(3H)-ones (C) were synthesized from 2-thioxo-1,2-dihydro-3-carbonitriles (A) via the 3-amino-thieno[2,3-b]pyridine-2-carboxamides (B). Substances of structure A were converted to 3-amino-thieno[2,3-b]pyridine-2-carbonitriles (G) which yielded the desired 4-amino substituted compounds I via the tricyclic 4-chloro-pyrido[3',2':4:5]thieno[3,2-d]1,2,3-triazines (H) by the reaction with N-nucleophiles. Some of the investigated compounds showed a respectable antianaphylactic activity.